Vertical drainage system

ABSTRACT

A vertical drainage system for a basement or other below grade foundation wall having a sealer coat on its outer surface, a filamentary web or sheet composed of a fiber-forming synthetic thermoplastic polymer, preferably in the form of rows of looped amorphous melt-spun and bonded filaments, being laid along the wall between its outer sealer coat and the adjacent earth, and pipe means or the like near the bottom or footing of the wall to drain off water percolating downwardly through the filamentary filter layer.

{451 Aug. 2a, 1973 McDuff et al. Nottebohm et ABSTRACT 3,093,583 6/19633,687,759 8/1972 Werner et 373,946 11/1887Richardson........................... 3,103,789 9/1963 3,378,398 4/1968Primary Examiner-Alfred C. Perham Attorney-John l-l. Shurtleff et a].

A vertical drainage system for a basement or other below gradefoundation wall having a sealer coat on its outer surface, a filamentaryweb or sheet composed of a fiber-forming synthetic thermoplasticpolymer, preferably in the form of rows of looped amorphous meltspun andbonded filaments, being laid along the wall between its outer sealercoat and the adjacent earth, and pipe means or the like near the bottomor footing of the wall to drain off water percolating downwardly throughthe filamentary filter layer.

10 Claims, 2 Drawing Figures Remscheid-Lennep; Wilhelm Herveiing,Wuppertal-Elberfeld; Helmut Werner, Elsenfeld; Hans Stapp, Momlingen,all of Germany Assignee: Akzona incorporated, Asheville,

Oct. 20, 1971 Foreign Application Priority Data Oct. 29, 1970Germany..........,.,....

U.S. Cl....................52/169,52/309, 161/150 Int.Cl. Field ofSearch..............................

References Cited UNITED STATES PATENTS 4/1972 l-lealy et United StatesPatent Daimler et al 4] VERTICAL DRAINAGE SYSTEM [75] Inventors:Berthold H. Daimler,

221 Filed:

{21] Appl. No.: 190,742

FlGi

Patented Aug. 28, 1973 FIG, 2

1 VERTICAL DRAINAGE SYSTEM In the construction of buildings, it has beenconventional to provide its foundation walls used for basements, cellarsor the like with a sealing layer as well as a sealer coat in order toprevent seepage or penetration of water or moisture into the masonrywall of the foundation structure. The water which is blocked or dammedup by such layers or coatings can be referred to as pressure water. Inorder to avoid a highly expensive water-impermeable sealing of the wall,i.e., one which must also be able to withstand this pressure water, ithas been proposed that a porous filter layer be introduced between theearth and the sealing coat so as to quickly conduct the water off in avertical direction.

With known vertical drainage systems, the porous filter layer consistsfor example of a graded gravel bed, i.e., wherein a coarse gravel orother aggregate is deposited near the drain pipe or similar conduit atthe bottom of the wall, while the uppermost layer consists of a veryfine gravel or sand to prevent clogging of the bed. These known filterlayers are thus constructed to provide a gradual or stagewise variationof porosity in a vertical direction.

Although a gravel bed having a width or thickness (measuredhorizontally) of about 20 cm. may be sufficient to achieve the desireddrainage, a thickness of at least about 60 cm. is generally chosen sincesafety regulations and construction specifications require that theoriginal excavation be accomplished such that after the foundation wallis raised, the workman applying the sealer coat or layer can workwithout danger. In other words, a trench of at least about 60 cm. inwidth remains between the sealer coat on the wall and the inner earthenwall of the excavation. To first partly fill this trench with earth inorder to reduce the drainage trench to a width of 20 cm. would not onlybe too costly but also too dangerous on account of the possibility ofdamaging the sealer coat. For this reason, one simply introduces gravelinto the entire trench. Even then, extreme care must be exercised toavoid damage to the sealer coat or layer.

A gravel bed for drainage is thus rather uneconomical due to theunnecessarily wide bed construction and only conceals the potentialdanger of damage to the sealing layer.

In another known vertical drainage system, a porous checker-brick isused as the filter layer. The brick available at the construction siteis stocked or piled to produce the drainage. This avoids some of thedisadvantages of a gravel bed drainage system, but on the other hand itis much more expensive in terms of the hand labor required. Moreover, avariation in porosity over the height of the filter cannot be easilyprovided.

One object of the present invention is to provide a vertical drainagesystem for foundation walls in which a filter layer can be installedquickly and without damage to the sealer coat on the outer wall surface.Another object of the invention is to provide a filter layer or memberwhich occupies only a slight space so that the necessary earthexcavation can be kept smaller from the outset. Yet another importantobject of the invention is to provide a vertical drainage system whichis substantially self-cleaning. In particular, it is especially intendedthat the drainage system of the invention prevent the entrainment ofearth particles into the filter layer with a sudden or heavy flow ofwater around and toward the foundation, i.e., so as to prevent stoppageof the filter or any excessive damming or retention of water against thefoundation. These and other objects and advantages of the invention willbecome more apparent upon consideration of the following detailedspecification.

It has now been found, in accordance with the invention, that a verticaldrainage system or combination with a conventional foundation wallhaving an outer sealer coat if one provides between this sealer coat andthe earth adjacent to the foundation a coarsely porous fleece web as thefilter layer laid along the wall, preferably in surface contact with itsone side against the outer sealed surface of the wall and with its otherside against the earth, ground or other fill subject to the effects ofrain or other surface water flowing therethrough. This fleece webemployed as the filter layer of the invention is composed of filamentsof a fiberforrning synthetic thermoplastic polymer, preferably melt-spuncontinuous amorphous filaments which are looped and spun-bonded atrandom overlapping points to provide a coherent, firm and porousstructure.

The term fleece web" is employed herein to include not only thepreferred continuous filaments but also a consolidated fibrous fleecematerial composed of cut staple fibers of a synthetic polymer, e.g., anywaterlaid or airlaid filamentary structure which is preferably bondedwhere the filaments or fibers contact each other to provide a reasonablyfirm and very open or porous structure. In this connection, the termcoarsely porous is employed herein to define a filter layer having aporosity of at least 40 percent and preferably 50 percent or more, i.e.,so that the voids or empty space of the total filter volume correspondsto these percentages.

The fleece web filter layer of the invention is easily installed sinceit can be cut into lengths in the form of a number of strips and thesecan be adhered one after the other onto the sealing coat or layer on theouter surface of the foundation wall. Any conventional adhesive for thefilamentary material of the fleece web can be used, or it is evenpossible to employ the sealing coat itself as the adhesive agent, i.e.,where a liquid, highly adhesive, waterproofing coating material is firstapplied to the wall surface to form an initially tacky layer or filmthereon and the fleece web of the invention is then immediately laidonto the tacky surface before it has an opportunity to dry. In thisinstance, one should select a conventional waterproofing agent which isadherent for both the masonry material of the wall and the thermoplasticpolymer substance of the fleece web.

The invention is illustrated by way of example in the accompanyingdrawing wherein:

FIG. I is a partly schematic cross-sectional view taken through aportion of the construction site to show one preferred embodiment of thefoundation wall vertical drainage system of the invention; and

FIG. 2 is a schematic side elevational view of a length of a preferredfleece web used as the filter layer of the invention (shown in ahorizontal-position in this instance).

As shown in FIG. ll, the foundation or masonry wall I is constructed inany conventional manner and the sealing coat or layer 2 applied to theoutwardly facing wall thereof at least below grade or below the finalground level and preferably at least a short distance above or up to thetop of the foundation if desired.

Onto this sealing coat 2 there is adhered the consolidated and coherentfleece web 3, such that the entire foundation wall 1 located below gradeis covered by this web as the filter layer of the drainage system. Theloose earth 4 originally removed for construcion purposes is then filledback in up to the desired ground level, the drainage pipe 5 first beinglaid near the bottom of the foundation and in close proximity to thefilter layer or web 3.

The footing 6 of the foundation is preferably adapted to extendhorizontally outwardly of the vertical wall 1 to accommodate both thefilter layer 3 and the drainage pipe 5 laid parallel to the wall 1. Thisnot only permits the proper positioning of the drainage pipe and itsassociated filter layer but also tends to seal off the bottom of thefoundation with the flow of water in the drainage system being directedpreferentially from the filter layer 3 into the pipe 5. Such drainagepipes 5 are usually laid completely around the entire foundationenclosing a basement, celler or the like, together with otherconventional conduit means to draw or conduct the water away from thebuilding structure, for example into storm sewers or the like. Theconnection and arrangement of such drainage pipe means is well known anddoes not constitute part of this invention except as to the initialplacement of at least one such drain pipe 5 near the bottom of thefoundation wall 1. In other respects, the final outflow of water can beaccomplished according to any conventional means and the verticaldrainage system of the invention is readily adapted to a wide variety ofdrainage pipe means.

The initial excavation line 7 is indicated schematically in FIG. 1,e.g., where it follows the basement floor with a downwardly projectingportion for the footing 6 and then outwardly to the surrounding earth 8so as to remove that portion of earth designated by the numeral 4 to awidth designated as B. This width is sufficient to permit a workman toeasily apply the waterproofing or sealing coat and also requiredadditional adhesive onto the outer wall surface of the foundation 1. inmost instances the footing 6 together with a short segment of the wall 1is first poured and set in place, and the remainder of the wall 1 isthen raised and formed on the lagging 9 which is usually a wood or metalinsert designed to provide a load supporting and/or insulating functionbetween the upper wall and its footing.

In FIG. 1, the geometric proportions are shown approximately in scalesize; with a trench width B between the sealing coat 2 and theunexcavated earth 8 of about 60 cm., the width or thickness of thefleece web 3 as the filter layer amounts to only about 10 percent of thetrench width, i.e., about 6 cm. The remaining 90 percent or 54 cm. isthus refilled with the loose earth or any other suitable filling 4. Forexample, some gravel, sand or other aggregate can be mixed in with theloose earth so that the refilled zone 4 is somewhat more porous than inits original unexcavated form. However, this is not essential and wouldnormally be adopted only where waste aggregate is readily available atthe building site.

As shown in FIG. 1 and further illustrated in an enlarged view in FIG.2, the preferred fleece web 3 used for purposes of the present inventionhas one side 3' facing the earth 4 of lower porosity and the other side3" facing the sealing coat 2 of higher porosity. The less open or moredense side 3 as indicated by more compact loops of filament is thusturned toward the earth 4 while the more open and less dense side 3" asindicated by the larger loops of filament is fastened to the sealinglayer 2 (compare FIG. 1).

An especially good openness or self-cleaning effect of the filter layer3 is achieved when this difference of porosity on either side of thelayer is maintained throughout the vertical drainage system, i.e., toprovide a substantially uniform horizontal variation in porosity overthe vertical height of the filter layer. Of course, one can also providesome variation of porosity in the vertical direction by using a numberof horizontal bands or lengths of the fleece web of different density orporosity. However, very good results have been achieved simply byvarying the porosity only as between the wall side and the earth side ofthe intermediate filter layer. As water flows from the ground or earth 4into the filter layer 3, suspended or entrained solid particles oflarger size tend to be filtered off and maintained outside of the filterlayer while smaller particles of solids tend to be washed entirelythrough the system by the percolating water as it flows downwardly intothe drainage pipe means. The requisite horizontally varied or stagedporosity is thus a special advantage of the vertical drainage system ofthe invention.

The difference in porosity of the fleece web can be realized in a numberof ways, for example by laminating or laying together two or more fleecewebs of different porosities and arranging them on the sealing coat orouter waterproofed wall surface of the foundation such that there is astagewise increase in porosity from the side facing the earth to theside facing the wall surface. However, other techniques can also beemployed, especially by using the particularly preferred construction ofthe fleece web described more fully hereinbelow.

Especially good results have been achieved when the porosity of thefilter layer or fleece web on the side facing the earth lies betweenabout 50 percent and percent while the porosity of the opposite sidefacing the sealing coat on the wall lies between about percent andpercent. In such cases, a better-than-average filtration effect isachieved on the outer or earth side of the filter layer while water isstill conducted very well on the inner or wall side of the filter layer.

According to the invention, an especially preferred embodiment of thefleece web is one in which continuous filaments are employed to form thefleece or porous but coherent web of a fiber-forming synthetic polymer.

In particular, it has been found to be most desirable to employ a fleeceweb insert or filter layer which is composed of a plurality ofcontinuous, substantially amorphous, melt-spun synthetic thennoplasticpolymer filaments which are arranged in approximately parallel rows inthe fonn of sinuous to helical loops in overlapping relationship witheach other, especially from looped filament to looped filament, with aself-bonding at random overlapping points of filament intersection. Theindividual loops of a single filament are generally formed approximatelyaround a linear axis extending lengthwise of the finished web, withsubstantially parallel axes for all of the looped, overlapping andbonded filaments. The filament loops may thus appear somewhat ashelically or spirally coiled springs in overlapping parallel rows and/orsome or all of the loops may be flattened along the coil axis of eachindividual filament.

These particular fleece web structures can be formed according to theearlier disclosed processes in copending applications Ser. No. 807,301,filed Mar. 14, 1969 now US. Pat. No. 3,687,759, and Ser. No. 378,615,filed Nov. 21, 1969 now US. Pat. No. 3,691,004, the disclosures of whichare incorporated herein by reference as fully as if set forth in theirentirety.

In producing these preferred fleece webs, as schematically illustratedin FIGS. 1 and 2 where rows of sinuous to helical loops extend withtheir axes lengthwise and with a number of rows across the width orthickness of the web, it is thus preferred to spin the individualfilaments from a spinning head as a polymer melt through spinningorifices arranged to provide the desired number of rows of loopedfilaments. The filaments are spun directly onto the surface of a waterbath and are initially collected or supported on the surface of the bathin the form of a coil or loop which is then drawn downwardly forsolidification below the bath surface. Adjacent coils or loops tend tobond with each other at the bath surface or short distance therebelowbefore the filaments have had a chance to completely solidify.

The density or porosity of the resulting fleece web when using thesespecial processes can be controlled by the size and placement of theindividual spinning orifices in the spinning head or nozzle plate. Adenser structure or lower porosity is ordinarily achieved by usingsmaller spinning openings which are also arranged in closer proximity toeach other. Larger filaments, preferably from orifices which are alsomore widely spaced, form correspondingly larger loops and lead to arelatively high porosity and a stiffer or less resilient structure. Thearrangement of smaller orifices along one portion and larger orificesalong the other portion in the face of the nozzle plate of the spinninghead can therefore be utilized to produce a corresponding variation indensity or porosity over the width of the resulting self-bonded,amorphous and looped filaments.

It is also possible, however, to produce this type of fleece web with alower porosity on the underneath side and a higher porosity on the topside by melt-spinning filaments of the same diameter onto the surface ofthe aqueous cooling bath to form the desired loops while also insertinga smooth metal or ceramic deflecting plate a short distance below thesurface of the bath at an angle to said surface of about to 80. Theposition of this plate with reference to the nozzle plate or face of thespinning head is chosen such that one outer row of the band of emergingfilaments meets approximately at the line of intersection between thedeflecting plate and the bath surface, this outer row corresponding tothe bottom" row of filaments as the band of filaments then rests andtravels over the surface of the deflecting plate. The freshly spun andstill highly plastic filaments lie on the bath surface to form loopswhile practically free of other influences except the buoyancy exertedon the filaments by the bath. Since the outer or bottom row of filamentstends to meet both the bath and the deflecting plate at the same time,i.e., so as to almost simultaneously contact the bath surface and theplate. These filaments are deflected from their normal path and positionso as to lie almost parallel to the web plane or outermost web surfaces,i.e., the bottom side of the web as it is laid flat on the plate. Aneven greater adhesion occurs on this flattened side of the web due tothe more densely positioned points of contact of the intersectingfilaments. The filaments of the adjacent rows lying higher above thedeflecting plate and contacting it after somewhat greater cooling arelikewise deflected or deformed from their initial position more stronglytoward the plane of the plate the closer each row of filaments is towardthe intersecting line of the plate and bath. The row of filaments in theband furthest away from this plate/bath intersecting line are influencedthe least and may substantially retain the initial loop position whichis almost perpendicular to the base or bottom of the web on thedeflecting plate.

it is especially preferable for purposes of the present invention toprovide such looped and partially deformed rows of overlapping filamentsin such a manner that while the bottom loops are almost parallel to thedeflecting plate, the upper loops are arranged at an angle of not morethan 60 with reference to the level plane of the overall web. Also, thedensity must decrease from the bottom to the top of the web, preferablyin accordance with the preferred values of porosity according to thisinvention. The porosities between the upper and lower sides of this web,i.e., in the intermediate rows or layers of looped filaments, then liesomewhere between the preferred values of each opposing side and in arelatively gradual variation from top to bottom.

In this manner, one can achieve especially useful filter layers orfleece webs for use in this invention without laminating separate fleecelayers or gluing or adhering two or more distinct fleece layers to eachother to provide the desired difference in porosity transversely of theelongated fleece web, i.e., horizontally to the final vertical positionof the filter layer in the drain age system.

it is sufficient to employ a fleece web with a thickness ofapproximately 5 to 10 cm. so that this size of web is especiallypreferred. On the other hand, with difficult soil conditions it is alsopossible to use a fleece web as the filter layer of larger thickness,e.g., up to about 13 cm. Since these fleece webs are not only highlyporous and light in weight but also relatively thin sheets or bands,they are very easily applied onto the waterproofed and adhesively coatedfoundation wall. The labor required is minimal and there is practicallyno possibility of damage to the sealing coat during application of thefilter layer or in refilling the trench with earth to complete theinstallation of the drainage systern.

Since the fiber-forming polyamides (nylons) such as polycaprolactam andpolyhexarnethylene adiparnide are quite resistant to rotting ordecomposition under all kinds of soil conditions as well as having othervaluable properties such as abrasion resistance and the like, they areespecially preferred in providing the filamentary material of the fleeceweb used as a filter layer in accordance with the invention. it will beunderstood, however, that many other fiber-forming syntheticthermoplastic polymers are also useful for the filter layer of theinvention, for example linear polyesters such as polyethyleneterephthaiate, polyolefins such as polypropylene or other additionpolymers such as polyvinyl chloride or the like. All of thesethermoplastic polymers can be readily melt-spun and then preferablyformed into the fleece web as looped continuous filaments bonded atrandom points of intersection.

Individual filament diameters of about 0.1 to 1 mm. are especiallypreferred in the production of the webs by melt spinning onto thesurface of an aqueous cooling bath as explained above. These relativelylarge filaments in the substantially amorphous form of the polymer,e.g., nylon, provide a very coherent and relatively rigid structure inthe transverse direction so as to withstand compression between thefoundation wall and the surrounding soil. At the same time, the desiredvariation in density or porosity in this transverse direction can alsobe predetermined and maintained after installation of the verticaldrainage system.

The vertical drainage system according to the present invention isparticularly designed to handle a large flow or percolation of water,e.g., during severe rain storms, thereby quickly relieving pressure onthe foundation wall as well as providing means to gradually withdrawunderground water adjacent a building foundation. The self cleaningaction of the drainage system of the invention is of value not only inthe proper functioning and long life of the filter layer but also in theavoidance of a dense moist material which encourages root growth fromtrees, shrubs or other vegetation. Although it is feasible to add othermaterials or elements in the vertical drainage system of the invention,the simplicity and relatively low cost of the fleece web as theessential filter layer is of particular advantage in avoiding complexstructures and building construction methods.

The invention is hereby claimed as follows:

1. A vertical drainage system for a basement foundation wall having awater impervious sealer coat on its outer surface, said systemcomprising a porous filter layer laid along said wall between saidsealer coat and the earth adjacent the foundation, said filter layerbeing a non-woven fleece web composed of filaments of a fibet-formingsynthetic thermoplastic polymer, and a drainage pipe means arranged nearthe bottom footing of said foundation wall to lead off water percolatedthrough said filter layer.

2. A vertical drainage system as claimed in claim 1 wherein that side ofthe fleece web facing the earth has a lower porosity than the oppositeside facing the sealer coat.

3. A vertical drainage system as claimed in claim 1 wherein said fleeceweb consists of continuous filaments of said fiber-forming synetheticthermoplastic polymer.

4. A vertical drainage system as claimed in claim 1 wherein said fleeceweb consists of a plurality of substantially amorphous filaments of amelt-spun polymer lying in rows of loops intersecting one another, saidfilaments being adhered to each other at random points of intersection.

5. A vertical drainage system as claimed in claim 4 wherein said fleeceweb has a thickness of about 5 to 6. A vertical drainage system asclaimed in claim 1 wherein that side of the fleece web facing the earthhas a porosity between about 50 and percent while the porosity of theopposite side of the fleece web facing the sealer coat is between aboutand percent.

7. A vertical drainage system as claimed in claim 1 wherein said fleeceweb is composed of a fiber-forming synthetic polyamide.

8. A vertical drainage system as claimed in claim 4 wherein saidmelt-spun polymer is a fiber-forming polyamide.

9. A vertical drainage system as claimed in claim 4 wherein the fleeceweb has a lower porosity on that side facing the earth than on theopposite side facing the sealer coat.

10. A vertical drainage system as claimed in claim 9 wherein said fleeceweb has a thickness of about 5 to 10 cm., a porosity on the side facingthe earth of about 50 to 70 percent and a porosity on the opposite sidefacing the sealer coat of about 85 to 95 percent.

1. A vertical drainage system for a basement foundation wall having awater impervious sealer coat on its outer surface, said systemcomprising a porous filter layer laid along said wall between saidsealer coat and the earth adjacent the foundation, said filter layerbeing a non-woven fleece web composed of filaments of a fiber-formingsynthetic thermoplastic polymer, and a drainage pipe means arranged nearthe bottom footing of said foundation wall to lead off water percolatedthrough said filter layer.
 2. A vertical drainage system as claimed inclaim 1 wherein that side of the fleece web facing the earth has a lowerporosity than the opposite side facing the sealer coat.
 3. A verticaldrainage system as claimed in claim 1 wherein said fleece web consistsof continuous filaments of said fiber-forming synethetic thermoplasticpolymer.
 4. A vertical drainage system as claimed in claim 1 whereinsaid fleece web consists of a plurality of substantially amorphousfilaments of a melt-spun polymer lying in rows of loops intersecting oneanother, said filaments being adhered to each other at random points ofintersection.
 5. A vertical drainage system as claimed in claim 4wherein said fleece web has a thickness of about 5 to 10 cm.
 6. Avertical drainage system as claimed in claim 1 wherein that side of thefleece web facing the earth has a porosity between about 50 and 70percent while the porosity of the opposite side of the fleece web facingthe sealer coat is between about 85 and 95 percent.
 7. A verticaldrainage system as claimed in claim 1 wherein said fleece web iscomposed of a fiber-forming synthetic polyamide.
 8. A vertical drainagesystem as claimed in claim 4 wherein said melt-spun polymer is afiber-forming polyamide.
 9. A vertical drainage system as claimed inclaim 4 wherein the fleece web has a lower porosity on that side facingthe earth than on the opposite side facing the sealer coat.
 10. Avertical drainage system as claimed in claim 9 wherein said fleece webhas a thickness of about 5 to 10 cm., a porosity on the side facing theearth of about 50 to 70 percent and a porosity on the opposite sidefacing the sealer coat of about 85 to 95 percent.